JP6661066B2 - Communication device, shielding prediction method, control circuit, and program storage medium - Google Patents

Description

  The present invention relates to a communication apparatus and a communication prediction method for performing communication in an environment where a communication path is expected to be periodically blocked.

  In an environment where a signal is periodically shielded, the communication device has lower communication efficiency than in a case where a signal is not shielded. One example of communication in such an environment is a helicopter satellite communication system. The helicopter satellite communication system is a system in which a helicopter and a ground station communicate via a communication satellite. The signal transmitted from the helicopter to the communication satellite is periodically interrupted by the helicopter rotor. Further, signals transmitted from the communication satellite to the helicopter are also periodically cut off by the helicopter rotor. Therefore, communication by the communication device mounted on the helicopter has lower efficiency than ordinary communication.

  Patent Literature 1 discloses that a flying station mounted on a flying object includes a receiver for detecting a reception level of a signal received from a fixed station via a communication satellite, and a radio wave on a propagation path is determined based on a reception level of the receiver. A technique for detecting a shielding timing is disclosed. When transmitting a signal to a fixed station via a communication satellite, the flying station transmits a signal based on the reception level when the radio wave is not shielded, and stops transmitting the signal when the radio wave is shielded. Further, the flying station detects a reception timing from the detected reception level, and detects a phase difference between the reception timing and the shielding timing. The flight station notifies the fixed station via the communication satellite of the phase difference, and the fixed station transmits a signal based on the phase difference only when there is no occlusion. The flight station can perform communication at a timing at which radio waves are not shielded by the rotating wings, and efficient communication is possible.

Japanese Patent No. 2503883

  However, according to the above-described conventional technique, the flying station detects the shielding timing, the reception timing, and the phase difference based on the reception level of the signal to be received. Therefore, there is a problem that the detection accuracy is easily affected by the instantaneous fluctuation of the reception level, and high-accuracy and stable detection cannot be performed.

  The present invention has been made in view of the above, and an object of the present invention is to provide a communication device capable of improving the accuracy of estimating a cycle in which a communication path is blocked.

  In order to solve the above-described problem and achieve the object, a communication device of the present invention includes a signal determination unit that determines the presence or absence of a received signal, and a device that transmits a received signal using a determination result of the signal determination unit. And a period estimating unit for estimating a shielding period in which a signal transmitted from the device is shielded. The period estimating unit calculates a differential value of the determination result, and calculates a provisional period of the shielding period using the differential value, and based on the internal state indicating the operation state of the period estimating unit, calculates the differential value and the provisional period. A mask processing unit that controls the use of the cycle and outputs a provisional cycle to be used. Further, the period estimation unit uses the provisional period output from the mask processing unit to calculate the occlusion period, and uses the provisional period output from the mask processing unit to determine a section in which the received signal is present. And a signal-equipped section calculation unit for calculating the signal-equipped section to be indicated. Further, the cycle estimating unit uses the provisional cycle output from the mask processing unit and the signal-equipped section to estimate a cycle timing indicating a timing of changing from a section where no received signal is present to a signal-present section in the determination result. It is characterized by including a timing estimating unit and a state determining unit that determines an internal state by using the shielding period.

  ADVANTAGE OF THE INVENTION The communication apparatus concerning this invention has the effect that the estimation accuracy of the period which a communication path is blocked can be improved.

FIG. 1 is a diagram illustrating a configuration example of a communication system according to a first embodiment; FIG. 2 is a block diagram illustrating a configuration example of a receiving device included in the communication device according to the first embodiment; 5 is a flowchart showing the operation of the receiving apparatus according to the first embodiment. 5 is a flowchart illustrating an operation of estimating a shielding period in the period estimating unit according to the first embodiment; FIG. 5 is a diagram illustrating an example of a determination result by a signal determination unit and a differential value calculated by a differentiation processing unit of the receiving device according to the first embodiment; 5 is a diagram illustrating an example of a determination result by a signal determination unit and a shielding period calculated by a period calculation unit of the receiving device according to the first embodiment; FIG. 4 is a diagram illustrating an example of a time at which a falling period or a rising period is input from a mask processing unit in the period calculating unit according to the first embodiment; FIG. 3 is a block diagram illustrating a configuration example of a transmission device according to the first embodiment. 5 is a flowchart illustrating the operation of the transmitting apparatus according to the first embodiment. FIG. 4 is a diagram showing an example of a case where a processing circuit included in the receiving device according to the first embodiment is configured by a processor and a memory; FIG. 3 is a diagram illustrating an example of a case where a processing circuit included in the receiving device according to the first embodiment is configured by dedicated hardware; FIG. 9 is a block diagram illustrating a configuration example of a receiving device included in the communication device according to the second embodiment. 9 is a flowchart illustrating an operation of estimating a shielding period in the period estimating unit according to the second embodiment. FIG. 9 is a diagram illustrating an example of a smoothing process performed by a smoothing unit according to the second embodiment; FIG. 9 is a block diagram illustrating a configuration example of a receiving device included in the communication device according to the third embodiment. 9 is a flowchart illustrating an operation of estimating a shielding period in the period estimating unit according to the third embodiment. FIG. 14 is a block diagram showing a configuration example of a receiving device included in the communication device according to the fourth embodiment. 11 is a flowchart illustrating an operation of estimating a shielding period in the period estimating unit according to the fourth embodiment. 11 is a flowchart illustrating an operation of determining the non-periodicity of occlusion in the non-periodic determination unit according to the fourth embodiment. 11 is a flowchart showing the operation of transmission control in the transmission control unit of the transmission device according to the fourth embodiment. FIG. 14 is a block diagram showing a configuration example of a receiving device included in the communication device according to the fifth embodiment. 11 is a flowchart showing the operation of the receiving apparatus according to the fifth embodiment. In the receiving apparatus according to the fifth embodiment, a diagram illustrating an example of a periodic signal generated by the periodic signal generation unit when the internal state is the specific period state. 11 is a flowchart illustrating an operation of transmission control in the transmission control unit of the transmission device according to the sixth embodiment. FIG. 14 is a diagram showing a method for determining a burst signal length in the transmission control unit according to the sixth embodiment. FIG. 17 is a diagram illustrating an example of symbol arrangement by transmission control of a transmission control unit in the transmitting apparatus according to the seventh embodiment.

  Hereinafter, a communication device and an occlusion prediction method according to an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited by the embodiment.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration example of the communication system 110 according to the first embodiment of the present invention. The communication system 110 includes a helicopter 103, a communication satellite 104, and a ground station 105. The communication system 110 is a helicopter satellite communication system in which the helicopter 103 and the ground station 105 communicate via the communication satellite 104. The helicopter 103 includes a communication device 100 including a reception device 200 and a transmission device 300. In the helicopter 103, a rotary wing 102 for providing buoyancy and propulsion is installed above the airframe 101. In the communication system 110, the communication path between the communication device 100 of the helicopter 103 and the communication satellite 104 is periodically shielded by the rotation of the rotor 102. The communication in which the communication path is periodically shielded may be a case in which communication is performed by a drone, a windmill, or the like, but is not limited thereto. In the present embodiment, communication device 100 estimates a cycle in which a communication path is blocked by rotation of rotary wing 102, and performs communication in consideration of a cycle in which the communication path is blocked.

  First, the configuration and operation of the receiving device 200 included in the communication device 100 will be described. FIG. 2 is a block diagram illustrating a configuration example of the receiving device 200 included in the communication device 100 according to the first embodiment. FIG. 3 is a flowchart illustrating the operation of the receiving apparatus 200 according to the first embodiment. The receiving device 200 includes an antenna 210, a signal determination unit 220, and a cycle estimation unit 230. The antenna 210 receives a signal transmitted from the communication satellite 104 and periodically shielded by the rotor 102 (step S1).

  The signal determination unit 220 determines the presence or absence of a received signal based on the reception state at the antenna 210 (Step S2). Specifically, the signal determination unit 220 compares the signal level of the received signal, which is a signal received by the antenna 210, with a predetermined determination threshold for determining the presence / absence of a signal. The presence or absence of a signal is determined based on the signal. The presence of a signal indicates that there is a received signal, and the absence of a signal indicates that there is no received signal. A method for determining the presence or absence of a received signal is not limited, but an example will be described. The signal determination unit 220 converts a received signal input from the antenna 210 into a received IQ signal composed of two orthogonal signals by, for example, digital signal processing, and a certain period (hereinafter, this fixed period is defined as one block). ), Calculate signal power of one block for a plurality of received IQ signals. The signal determination unit 220 performs an averaging process on the calculated signal power by IIR (Infinite Impulse Response) averaging or simple averaging to calculate an average signal power value. The signal determination unit 220 compares the calculated average signal power with the determination threshold. When the average signal power value is equal to or greater than the determination threshold, the signal determination unit 220 determines that there is a received signal, that is, determines that there is a signal, and determines a determination result “1” indicating presence or absence of a received signal for one block. Output. If the average signal power value is less than the determination threshold, the signal determination unit 220 determines that there is no received signal, that is, determines that there is no signal, and determines a determination result “0” indicating the absence of a signal for the presence or absence of a received signal for one block. Output.

  The period estimating unit 230 estimates a shielding period in which a signal transmitted from the transmission source device, in the example of FIG. 1, the communication device 104 to the communication device 100 is blocked, using the determination result of the signal determination unit 220 (step). S3). Specifically, as a series of operations for estimating the shielding period, the period estimating unit 230 changes from “0” to “1” in the shielding period indicating the period in which the signal is shielded and the determination result of the signal determining unit 220. A cycle timing indicating a timing, a signaled section indicating a section in which a received signal exists between one shielding cycle, and an internal state indicating an operation state of the cycle estimation section 230 are generated. Among these, the unit of the shielding cycle, the cycle timing, and the section with a signal is a block, and takes an integer value. As shown in FIG. 2, the cycle estimating section 230 includes a differentiation processing section 231, a mask processing section 232, a cycle calculating section 233, a state determining section 234, a cycle timing estimating section 235, and a signal section calculating section 236. And. The differential processing unit 231 calculates a differential value for the determination result of the signal determination unit 220. The mask processing unit 232 calculates a provisional period from the differential value calculated by the differentiation processing unit 231 and, based on the internal state, specifically, based on a condition set for the internal state, calculates the provisional period and the provisional period. Is masked. The cycle calculation unit 233 calculates a shielding cycle from the provisional cycle output from the mask processing unit 232. The state determination unit 234 determines the internal state of the cycle estimation unit 230 using the shielding cycle calculated by the cycle calculation unit 233. The cycle timing estimating unit 235 estimates the cycle timing using the provisional cycle output from the mask processing unit 232 and the signaled section calculated by the signaled section calculation unit 236. The signaled section calculation unit 236 calculates a signaled section from the provisional period calculated by the mask processing unit 232.

  The detailed operation of the cycle estimation unit 230 will be described. FIG. 4 is a flowchart illustrating an operation of estimating a shielding period in the period estimating unit 230 according to the first embodiment.

  The differential processing unit 231 calculates a differential value for the determination result output from the signal determination unit 220, that is, detects a rise and a fall of the determination result (Step S11). Specifically, when the determination result of the previous block is “0” (no signal) and the determination result of the current block is “1” (with signal), the differential processing unit 231 detects a rising edge and determines the differential value “ 1 "is output. When the determination result of the previous block is “1” (with a signal) and the determination result of the current block is “0” (without a signal), the differential processing unit 231 detects a falling edge and calculates a differential value “−1”. Output. In other cases, the differentiating unit 231 outputs a differential value “0”.

The mask processing unit 232 calculates a provisional period for the differential value calculated by the differentiation processing unit 231 (Step S12). The mask processing unit 232 calculates the provisional period when the differential value is “1” or “−1”, and does not calculate it when the differential value is “0”. When the differential value “1” or “−1” is input from the differential processing unit 231, the mask processing unit 232 calculates a provisional cycle from the difference between the previous time when the same differential value was input and the current time. FIG. 5 is a diagram illustrating an example of a determination result by the signal determination unit 220 and a differential value calculated by the differentiation processing unit 231 of the reception device 200 according to the first embodiment. FIG. 5A shows the determination result by the signal determination unit 220, where the horizontal axis represents time and the vertical axis represents the value of the determination result. FIG. 5B shows the differential value calculated by the differential processing unit 231. The horizontal axis indicates time, and the vertical axis indicates the differential value. As illustrated in FIG. 5, the differential processing unit 231 calculates a differential value “−1” at a timing when the determination result of the signal determination unit 220 falls, and a differential processing unit at a timing when the determination result of the signal determination unit 220 rises. Reference numeral 231 calculates a differential value “1”. The mask processing unit 232 is, for example, a differential value of the time t ₃ in FIG. 5 is "-1", the last time that the same differential value "-1" is input for the t _1, at time t ₃ The provisional period “t ₃ −t ₁ ” is calculated. Similarly, the mask processing unit 232 is a differential value of the time t ₄ in FIG. 5 is "1", since the same differential value "1" is the last time input becomes t _2, tentatively at time t ₄ The period “t ₄ −t ₂ ” is calculated. Here, the provisional period calculated when the differential value is “−1” is defined as the falling period, and the provisional period calculated when the differential value is “1” is defined as the rising period.

  The mask processing unit 232 controls the use of the differential value and the calculated provisional period based on the internal state. Specifically, the mask processing unit 232 performs a mask process of masking the differential value and the provisional period when a condition according to the internal state is satisfied (Step S13). Here, the internal state indicates the operation state of the cycle estimation unit 230 determined by the state determination unit 234, and includes two states: a cycle search state and a cycle identification state. The cycle search state is a state in which the shielding cycle is not specified in the cycle estimation unit 230. The cycle identification state is a state in which the cycle estimation unit 230 has identified the shielding cycle. A method of determining the internal state in the state determination unit 234 will be described later.

When the internal state is the period search state, the mask processing unit 232 compares the provisional period with a maximum period which is a predefined parameter. The mask processing unit 232 does nothing if the provisional period is less than the maximum period, and if the provisional period exceeds the maximum period, sets the provisional period to D ₀ (D ₀ is 2 or more) so that the provisional period is less than the maximum period. (Integer). At this time, the mask processing unit 232 selects the minimum value of D ₀ at which the division result is equal to or less than the maximum cycle. The provisional period exceeding the maximum period may be twice as large as the provisional period due to the masked differential value. Therefore, the mask processing unit 232 calculates a correct provisional period by dividing the provisional period exceeding the maximum period by an integer. Next, the mask processing unit 232 compares the provisional period with a minimum period which is a parameter defined in advance. When the provisional period is less than the minimum period, the mask processing unit 232 masks the differential value input to the mask processing unit 232 and the calculated provisional period. That is, when the internal state is the period search state, the mask processing unit 232 determines whether the provisional period is not within the range of the specified minimum period and the specified maximum period and the differential value input to the mask processing unit 232 and Do not use the calculated provisional period. When the provisional period is equal to or longer than the minimum period, the mask processing unit 232 outputs the calculated provisional period.

When the internal state is the cycle specific state, the mask processing unit 232 compares the provisional cycle with the specific cycle calculated by the cycle calculation unit 233. The specific cycle is a shielding cycle calculated by the cycle calculating unit 233 in the cycle specific state. The shielding cycle, that is, the specific cycle calculated by the cycle calculating unit 233 is the one calculated by the cycle calculating unit 233 in the previous operation. The mask processing unit 232 does nothing when the provisional period is equal to or less than “specific period + W _MS ” (W _MS is an allowable value of the mask processing), and when the provisional period exceeds “specific period + W _MS ”, “specific period + W _MS ”. _The provisional period is subtracted by “specific period × D ₁ ” so as to be less than “ _MS × D ₁ ” (D ₁ is an integer of 2 or more). At this time, the mask processing unit 232 selects the value of the minimum of D ₁ that the subtraction result is equal to or less than "specific cycle + W _MS × D _1". As in the case of the period search state, when a provisional period exceeding “specific period + W _MS ” is input, the mask processing unit 232 masks the differential value, and the provisional period is twice or more the original period. Since there is a possibility, a provisional period exceeding “specific period + W _MS ” is subtracted by “specific period × D ₁ ” to calculate a correct provisional period. Next, the mask processing unit 232 determines whether or not the provisional period is within the range of the upper limit M _max and the lower limit M _min obtained from the following equation (1). When the provisional period is out of the range of the upper limit M _max and the lower limit M _min , the mask processing unit 232 masks the differential value input to the mask processing unit 232 and the calculated provisional period. That is, when the internal state is the cycle specific state, and when the provisional cycle is not within the specified range including the specific cycle, the mask processing unit 232 calculates the differential value input to the mask processing unit 232 and the calculated provisional cycle. do not use.

M _max = min (C _max , C ₁ + W _MS × D ₁ )
M _min = max (C _min , C ₁ −W _MS × D ₁ ) (1)

In the equation (1), C _max indicates a maximum cycle, C _min indicates a minimum cycle, and C ₁ indicates a specific cycle. In equation (1), max (a, b) is a function that outputs a when a ≧ b and outputs b when a <b, and min (a, b) is a ≦ b Is a function that outputs a when b> b and outputs b when a> b.

  As described above, the mask processing unit 232 masks the differential value and the provisional period when the condition according to the internal state of the period estimation unit 230 is satisfied. The specific operation according to the presence or absence of the mask processing is as follows. When not masking the differential value, the mask processing unit 232 stores the time when the differential value is “−1” or “1” in order to calculate the provisional period. When masking the differential value, the mask processing unit 232 does not store the time when the differential value is “−1” or “1”. In addition, when not masking the provisional period, the mask processing unit 232 generates and outputs an enable signal together with the provisional period in order to use the calculated provisional period as an effective value. When masking the provisional period, the mask processing unit 232 does not output both the provisional period and the enable signal. When outputting the provisional period, the mask processing unit 232 outputs the provisional period in such a manner that the provisional period can be recognized as the provisional period of the rising period or the provisional period of the falling period.

  When acquiring the provisional period together with the enable signal, the period calculation unit 233 calculates the shielding period using the provisional period output from the mask processing unit 232 (step S14). FIG. 6 is a diagram illustrating an example of a determination result by the signal determination unit 220 of the receiving apparatus 200 according to the first embodiment and an example of a shielding cycle calculated by the cycle calculation unit 233. In FIG. 6, the horizontal axis indicates time, and the vertical axis indicates the value of the determination result. If the determination result of the signal determination unit 220 is ideal, as shown in FIG. 6, the shielding period is a section from the rise of the determination result to the rise of the next determination result, or from the fall of the determination result to the next determination result. Is the section up to the fall of. When the provisional period is input in the order of the falling period and the rising period from the mask processing unit 232, or when the provisional period is input in the order of the rising period and the falling period, the following formula is used. The shielding period is calculated from (2).

C = ( _Cr + _Cf ) / 2 (2)

In the formula (2), C denotes the shielding period, C _r represents the rising period, C _f denotes a falling period. As described above, since the shielding period takes an integer value, if the calculation result of Expression (2) is a decimal, the period calculating unit 233 rounds off C to an integer value. FIG. 7 is a diagram illustrating an example of a time at which the falling period or the rising period is input from the mask processing unit 232 in the period calculating unit 233 according to the first embodiment. 7, the horizontal axis indicates time, and the vertical axis indicates the differential value after the mask processing by the mask processing unit 232. Period calculating section 233 is, for example, is input falling period up to the time t ₅ shown in FIG. 7, if the cycle rising time t ₆ is input at time t _6, the falling period of the time t ₅ and time t _Using the rising cycle of _6, the shielding cycle is calculated from equation (2) and output. Period calculating section 233, as shown in FIG. 7, falling between times t ₈ and time t _9, i.e., the differential value "-1" is masked, continuously rising period is entered twice since it was not calculated time t ₉ the shielding period. The period calculation unit 233, since the falling period at time t ₁₀ is input at time t _10, with the falling period of the rising period and the time t ₁₀ at time t _9, shielded from equation (2) Calculate and output the period.

The state determining unit 234 determines the internal state of the period estimating unit 230 using the shielding period calculated by the period calculating unit 233 (Step S15). As described above, the internal state is defined as two states: a cycle search state and a cycle specific state. Here, in the cycle estimation unit 230, the initial state is a cycle search state. The state determination unit 234 determines whether a transition condition from the periodic search state to the cycle specific state is satisfied in the case of the periodic search state, and determines a transition condition from the cycle specific state to the periodic search state in the case of the periodic specific state. It is determined whether or not the condition is satisfied. The transition condition from the cycle search state to the cycle specific state is, for example, in the state determination unit 234, when the shielding period input at the current time, that is, when the latest shielding period calculated by the period calculating unit 233 is set as the reference period, shielding period of the past N _BK times is a case which is within the range of "reference period -W _BK" in the "reference period + W _BK". Here, _NBK is the number of backward protection stages, and an integer of 1 or more is set. W _BK is an allowable value for backward protection, and is set to an integer of 0 or more. The unit of the reference cycle is a block, which takes an integer value. The transition condition from the cycle specific state to the cycle search state is, for example, the state determination unit 234 monitors the update time of the specific cycle that is the shielding cycle calculated at the time of the cycle specific state. It is assumed that the specific period is not updated even after the period of “specific period × N _FR ” has elapsed. Here, N _FR is the number of forward protection stages, and an integer of 1 or more is set.

  The signaled section calculation unit 236 calculates a signaled section using the provisional cycle output from the mask processing unit 232 (step S16). The signal existence section is a section from the rise to the fall of the decision result as shown in FIG. 6 if the decision result of the signal decision section 220 is ideal. When the provisional period is input in the order of the rising period and the falling period, the signaled section calculation unit 236 calculates the signaled section from the following equation (3).

A = t _f −t _r (3)

In the formula (3), A represents the signal chromatic interval, t _f is the time at which the falling period is input, t _r represents the time at which the rising period is entered.

  The cycle timing estimation unit 235 estimates the cycle timing using the provisional cycle output from the mask processing unit 232 and the signaled section calculated by the signaled section calculation unit 236 (step S17). For example, if the determination result of the signal determination unit 220 is ideal, the cycle timing is a rising timing of the determination result as shown in FIG. That is, the cycle timing is a timing at which the determination result of the signal determination unit 220 changes from a section where no received signal exists to a section where a received signal exists. Therefore, when the provisional period input from the mask processing unit 232 is the rising period, the period timing estimation unit 235 sets the time at which the rising period is input as the period timing. When the provisional period input from the mask processing unit 232 is a falling period, the period timing estimating unit 235 estimates, as the period timing, a time at which the falling period has been input and returned to the past by a signal interval from the input time. I do.

  In receiving apparatus 200, cycle estimating section 230 outputs the internal state, the shielding cycle, the cycle timing, and the section with a signal to transmitting apparatus 300. The transmission device 300 controls transmission of a transmission signal using the internal state, the shielding period, the period timing, and the signal period acquired from the reception device 200. The configuration and operation of transmitting apparatus 300 will be described. FIG. 8 is a block diagram illustrating a configuration example of the transmitting apparatus 300 according to the first embodiment. FIG. 9 is a flowchart illustrating an operation of the transmitting apparatus 300 according to the first embodiment. The transmission device 300 includes a transmission control unit 310, a transmission signal generation unit 320, and an antenna 330.

  The transmission control unit 310 generates a transmission signal using the internal state, the shielding period, the period timing, and the signal period input from the reception device 200, and starts transmission, and a transmission signal to be generated. Is determined (step S21). The transmission control unit 310 determines the transmission start timing based on, for example, the cycle timing when the internal state is the cycle specific state. The transmission control unit 310 predicts the next and subsequent cycle timings based on the shielding cycle when the internal state is the cycle specific state, and if the cycle timing is not updated by the predicted next cycle timing, the predicted cycle timing Is determined as the transmission start timing. Further, transmission control section 310 determines the length of the transmission signal based on the signal presence section when the internal state is the cycle specific state. Transmission control section 310 generates a control signal including the determined transmission start timing and transmission signal length, and outputs the generated control signal to transmission signal generation section 320.

  The transmission signal generation unit 320 generates a transmission signal based on the transmission start timing and the transmission signal length included in the acquired control signal (Step S22). Then, the transmission signal generation section 320 transmits the transmission signal via the antenna 330 (Step S23).

  Subsequently, a hardware configuration of the receiving device 200 included in the communication device 100 will be described. In the receiving device 200, the antenna 210 is an antenna device. The signal determination unit 220 and the cycle estimation unit 230 are realized by a processing circuit. The processing circuit may be a processor and a memory that execute a program stored in the memory, or may be dedicated hardware.

  FIG. 10 is a diagram illustrating an example of a case where the processing circuit included in the receiving device 200 according to the first embodiment is configured by a processor and a memory. When the processing circuit includes the processor 91 and the memory 92, each function of the processing circuit of the receiving device 200 is realized by software, firmware, or a combination of software and firmware. Software or firmware is described as a program and stored in the memory 92. In the processing circuit, each function is realized by the processor 91 reading and executing a program stored in the memory 92. That is, the processing circuit includes a memory 92 for storing a program that results in the processing of the signal determination unit 220 and the cycle estimation unit 230 being executed. In addition, it can be said that these programs cause a computer to execute the procedures and methods of the signal determination unit 220 and the cycle estimation unit 230.

  Here, the processor 91 may be a CPU (Central Processing Unit), a processing device, an arithmetic device, a microprocessor, a microcomputer, a DSP (Digital Signal Processor), or the like. The memory 92 includes a non-volatile or volatile memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), and an EEPROM (registered trademark) (Electrically EPROM). Semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD (Digital Versatile Disc), and the like.

  FIG. 11 is a diagram illustrating an example of a case where the processing circuit included in the receiving device 200 according to the first embodiment is configured by dedicated hardware. When the processing circuit is configured by dedicated hardware, the processing circuit 93 illustrated in FIG. 11 includes, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), An FPGA (Field Programmable Gate Array) or a combination thereof is applicable. Each function of the signal determination unit 220 and the cycle estimation unit 230 may be realized by the processing circuit 93 for each function, or each function may be realized by the processing circuit 93 collectively.

  Note that each of the functions of the signal determination unit 220 and the cycle estimation unit 230 may be partially implemented by dedicated hardware, and partially implemented by software or firmware. As described above, the processing circuit can realize the above-described functions by dedicated hardware, software, firmware, or a combination thereof.

  Next, a hardware configuration of the transmitting device 300 included in the communication device 100 will be described. In transmitting device 300, antenna 330 is an antenna device. Transmission control section 310 and transmission signal generation section 320 are realized by a processing circuit. The processing circuit has the configuration shown in FIG. 10 or FIG. 11, similarly to the processing circuit included in the receiving device 200.

  As described above, according to the present embodiment, in communication apparatus 100, receiving apparatus 200 performs signal determination based on the signal level of the received signal, and determines the internal state indicating the operation state and communication apparatus 100 based on the determination result. A shielding period in which a signal to be transmitted is shielded, a period timing indicating a timing at which the determination result changes from a section where no received signal is present to a section where a received signal is present, and a signal-presenting section indicating a section where the received signal is present are obtained. . The transmitting device 300 determines the timing of generating the transmission signal and the length of the transmission signal using the internal state, the shielding period, the period timing, and the signal interval, and performs transmission. Accordingly, in an environment in which the communication path is expected to be periodically shielded, the communication apparatus 100 shields the communication path by masking the internal state having the number of protection steps and unexpected shielding detection. The accuracy of estimating the shielding period can be improved. Further, the communication device 100 can predict the next transmission start timing even if signal blocking cannot be detected by using the periodicity of the blocking period, so that more efficient communication can be performed.

Embodiment 2 FIG.
In the second embodiment, an averaging unit and a smoothing unit are added to the cycle estimation unit 230, and the shielding cycle, the cycle timing, and the section with a signal are estimated with higher accuracy than in the first embodiment. Parts different from the first embodiment will be described.

  FIG. 12 is a block diagram illustrating a configuration example of the receiving device 200a included in the communication device 100 according to the second embodiment. The receiving apparatus 200a according to the second embodiment shown in FIG. 12 is different from the receiving apparatus 200 according to the first embodiment shown in FIG. 2 in that the cycle estimating section 230 is replaced with a cycle estimating section 230a. The cycle estimation unit 230a is obtained by adding an averaging unit 401 and a smoothing unit 402 to the cycle estimation unit 230. In the example of FIG. 12, the processing is performed in the order of the averaging unit 401 and the smoothing unit 402. However, the processing may be performed in the order of the smoothing unit 402 and the averaging unit 401. In the present embodiment, a case will be described where processing is performed in the order of averaging section 401 and smoothing section 402 as shown in FIG. The operation of the receiving device 200a is the same as the operation of the receiving device 200 of the first embodiment shown in the flowchart of FIG. 3, but differs in the operation of estimating the shielding period in step S3. FIG. 13 is a flowchart illustrating an operation of estimating a shielding period in the period estimating unit 230a according to the second embodiment.

  The averaging unit 401 performs averaging processing on the determination result output from the signal determination unit 220 according to the internal state (step S31). Specifically, the averaging unit 401 does not perform the averaging process when the internal state is the period search state, and performs the averaging process when the internal state is the period specific state. The averaging unit 401 performs the averaging process using the specific cycle when the internal state is the cycle specific state, for example, in the case of averaging by simple averaging according to the following equation (4).

In the equation (4), d (t) indicates a determination result input from the signal determination unit 220 to the averaging unit 401 at time t, N _ave indicates an average number of simple averaging, and C ₁ indicates a specific cycle. S ₁ (t) indicates the accumulated value at time t. The shielding cycle, that is, the specific cycle calculated by the cycle calculating unit 233 is the one calculated by the cycle calculating unit 233 in the previous operation. The averaging unit 401 outputs “1” when “s ₁ (t) ≧ N _ave / 2” based on the accumulated value s ₁ (t) obtained by the equation (4), and outputs “s ₁ ( t) <N _ave / 2 ”,“ 0 ”is output. In the case of averaging by IIR averaging, the averaging unit 401 performs averaging processing by the following equation (5).

s ₂ (t) = d (t) × (1−α) + s ₂ (t−C ₁ ) × α (5)

In Expression (5), α indicates a forgetting factor, and α is between 0 and 1. The averaging unit 401 outputs “1” when “s ₂ (t) ≧ 0.5” based on the IIR average value s ₂ (t) obtained by Expression (5), and outputs “s ₂ ( If t) <0.5, “0” is output. As described above, the averaging unit 401 can improve the accuracy of the determination result by averaging the periodically input determination result using the specific cycle. Note that, when the processing is performed in the order of the smoothing unit 402 and the averaging unit 401 in the cycle estimation unit 230a, the averaging unit 401 performs the averaging process on the value input from the smoothing unit 402.

  The smoothing unit 402 performs a smoothing process on the value input from the averaging unit 401 (Step S32). Specifically, the smoothing unit 402 performs a smoothing process by executing a smoothing loop L times (L is an integer of 1 or more), which is a specified smoothing number. For example, in the processing of the n-th smoothing loop (n is an integer of 1 or more and L or less), the smoothing unit 402 calculates the value input from the averaging unit 401 at time t−n, time t, and time t + 1. In the case of “1”, “0”, and “1”, respectively, the value input at time t is corrected from “0” to “1”. Similarly, when the values input from the averaging unit 401 at time t−n, time t, and time t + 1 are “0”, “1”, and “0”, respectively, the smoothing unit 402 The input value is sometimes corrected from "1" to "0". Note that the time t is represented by a discretized value of the time at which the determination result is output from the signal determination unit 220, and the range of t is such that tn is a positive value.

FIG. 14 is a diagram illustrating an example of a smoothing process performed by the smoothing unit 402 according to the second embodiment. In FIG. 14, the graph of FIG. 14A shows an ideal value of the determination result in the signal determination unit 220, and the graph of FIG. 14B shows a state in which errors are mixed in the determination result from the averaging unit 401 to the smoothing unit. Reference numeral 402 denotes the input value. 14A to 14E, the horizontal axis represents time. FIG. 14 (c) shows the graph of FIG. 14 (b) with values for each block. The smoothing unit 402 performs a smoothing process according to a predetermined number L of smoothing loops. In FIG. 14, as an example, the smoothing process when L = 2 will be described. In the first processing of the smoothing loop, the smoothing unit 402 checks the values input at time t-1, time t, and time t + 1. In the example of FIG. 14, the values input at time t ₁₂ -1, time t ₁₂ , and time t ₁₂ +1 are “1”, “0”, and “1” in the example of FIG. the value entered at the time of t ₁₂ to correct the "0" to "1". The state at this time is shown in FIG. In the second processing of the smoothing loop, the smoothing unit 402 checks the values input at time t−2, time t, and time t + 1. In the example of FIG. 14, the values input at time t ₁₃ -2, time t ₁₃ , and time t ₁₃ +1 are “1”, “0”, and “1”. the value entered at the time of t ₁₃ corrects from "0" to "1". The state at this time is shown in FIG. As described above, the smoothing unit 402 can correct an erroneous value even when an erroneous value is input for two consecutive blocks by the second processing of the smoothing loop. Note that, when the processing is performed in the order of the smoothing unit 402 and the averaging unit 401 in the cycle estimation unit 230a, the smoothing unit 402 performs the smoothing process on the determination result output from the signal determination unit 220.

  The operation of the period estimating unit 230a after the differential processing unit 231 is the same as the operation in the first embodiment shown in the flowchart of FIG. Further, in the second embodiment, the hardware configuration of receiving apparatus 200a is the same as that of receiving apparatus 200 of the first embodiment.

  As described above, according to the present embodiment, in period estimation section 230a, averaging section 401 performs averaging processing on the determination result of signal determination section 220, and smoothing section 402 further performs smoothing. Was decided to be performed. Accordingly, the cycle estimation unit 230a can improve the accuracy of the determination result of the signal determination unit 220. Therefore, with the improvement of the accuracy of the determination result to be used, the estimation accuracy of the shielding cycle, the cycle timing, and the signal existence section is improved. Can be improved.

Embodiment 3 FIG.
In the third embodiment, a cycle averaging section, a cycle timing averaging section, and a signaled section averaging section are added to the cycle estimation section 230a, and the shielding cycle, the cycle timing, and the signal The existing section is estimated with higher accuracy. The parts different from the second embodiment will be described.

  FIG. 15 is a block diagram illustrating a configuration example of the receiving device 200b included in the communication device 100 according to the third embodiment. The receiving apparatus 200b according to the third embodiment shown in FIG. 15 differs from the receiving apparatus 200a according to the second embodiment shown in FIG. 12 in that the cycle estimating section 230a is replaced with a cycle estimating section 230b. The cycle estimation section 230b is obtained by adding a cycle averaging section 501, a cycle timing averaging section 502, and a signaled section averaging section 503 to the cycle estimation section 230a. The operation of the receiving device 200b is the same as the operation of the receiving device 200 of the first embodiment shown in the flowchart of FIG. 3, but differs in the content of the operation of estimating the shielding period in step S3. FIG. 16 is a flowchart illustrating an operation of estimating a shielding period in the period estimating unit 230b according to the third embodiment. In the flowchart shown in FIG. 16, the operations in steps S31 to S17 are the same as the operations in the second embodiment shown in the flowchart in FIG. 13, except that the cycle averaging section 501, the cycle timing averaging section 502, And the operation of the signaled section averaging section 503 is added.

After the operation in step S15, the cycle averaging section 501 performs averaging processing on the shielding cycle calculated by the cycle calculation section 233 according to the internal state (step S41). Specifically, the cycle averaging unit 501 does not perform the averaging process when the internal state is the cycle search state, and performs the averaging process when the internal state is the cycle specific state. That is, the cycle averaging unit 501 calculates an average shielding cycle obtained by averaging the specific cycle. The period averaging unit 501 can perform averaging processing by simple averaging, IIR averaging, and the like, and the averaging method is not particularly limited. For example, in the case of averaging using a simple average, the cycle averaging unit 501 accumulates the past N _cycle times of the shielding cycles updated by the cycle calculating unit 233 and divides the accumulated value by N _cycles to obtain the average shielding cycle. Calculate _Cave . Here, N _cycle indicates the average number of the shielding periods. Period averaging section 501 outputs the average shielding period to transmitting apparatus 300. Note that the mask processing unit 232 and the averaging unit 401 use the average shielding period calculated in the previous operation by the period averaging unit 501 as the shielding period, that is, the specific period.

After the operation of step S16, the signaled section averaging unit 503 performs averaging processing on the signaled section calculated by the signaled section calculation unit 236 according to the internal state (step S42). Specifically, similarly to the cycle averaging section 501 and the cycle timing averaging section 502, the signaled section averaging section 503 does not perform the averaging process when the internal state is the cycle search state, and sets the internal state to the cycle search state. The averaging process is performed in a specific state. The signaled section averaging section 503 can perform averaging processing by simple averaging, IIR averaging, or the like, similarly to the cycle averaging section 501 and the cycle timing averaging section 502, and the averaging method is not limited. As an example, an operation when a simple average is used will be described. When averaging by simple averaging, the signaled section averaging unit 503 accumulates the past N _avail times of signaled sections updated by the signaled section calculation unit 236, and divides the accumulated value by N _avail . The average signal existence section _Aave is calculated. Here, N _avail indicates the number of averages in the signal section. Signaled section averaging section 503 outputs the averaged signaled section to transmitting apparatus 300.

  After the operation in step S17, the cycle timing averaging unit 502 performs averaging processing on the cycle timing calculated by the cycle timing estimation unit 235 according to the internal state (step S43). Specifically, the cycle timing averaging unit 502 does not perform the averaging process when the internal state is the cycle search state, and performs the averaging process when the internal state is the cycle specific state, similarly to the cycle averaging unit 501. Perform processing. The periodic timing averaging unit 502 can perform averaging processing by simple averaging, IIR averaging, and the like, and the averaging method is not particularly limited. As an example, an operation when a simple average is used will be described.

The cycle timing averaging unit 502 performs averaging processing when the provisional cycle is input from the mask processing unit 232. When the provisional period is input to the period timing averaging unit 502, the provisional period is also input to the period timing estimation unit 235, and the period timing is calculated. Therefore, when the provisional cycle is input from the mask processing unit 232 to the cycle timing averaging unit 502, the cycle timing is input from the cycle timing estimation unit 235 to the cycle timing averaging unit 502. The cycle timing averaging unit 502 stores the input cycle timing in a memory. Further, the cycle timing averaging unit 502 calculates the falling time from the input provisional cycle. Specifically, when the tentative cycle is a rising cycle, the cycle timing averaging section 502 adds the average signal section calculated by the signal section averaging section 503 to the time at which the rising cycle is input, thereby causing the falling section to fall. The time is calculated, and when the provisional period is the falling period, the time when the falling period is input is set as the falling time. The cycle timing averaging unit 502 calculates a cycle timing adjustment value t _adj from the following equation (6) using the cycle timing stored in the memory and the calculated fall time.

In Equation (6), A _ave represents the average signal existence section calculated by the signal existence section averaging unit 503, t _f represents the calculated fall time, and _tr (x) is inputted in the x-th time in the past. shows the cycle timing was, C _ave represents the average shielding period calculated by the period averaging unit 501, N _tim represents the average number of cycle timing, mod (a, b) when obtained by dividing a by b Indicates the remainder. The cycle timing averaging unit 502 calculates the average cycle timing T _ave based on the cycle timing adjustment value t _adj calculated using Expression (6). When the input temporary period is a falling period, the period timing averaging unit 502 calculates the average period timing T _ave from the following equation (7).

T _ave = t + C _ave −A _ave + t _adj (7)

In the equation (7), t is the current time, and here indicates the time at which the falling period is input. When the provisional period input to the period timing averaging unit 502 is the rising period, the average period timing T _ave is calculated from the following equation (8).

T _ave = t + t _adj (8)

  In Expression (8), t is the current time, and indicates the time at which the rising cycle is input. Period timing averaging section 502 outputs the average period timing to transmitting apparatus 300.

  In the third embodiment, a cycle averaging section 501 and a signaled section averaging section 503 are added to the cycle estimation section 230a of the second embodiment. Accordingly, the averaging unit 401 and the mask processing unit 232 change the specific cycle to be used to the average shielding cycle calculated by the cycle averaging unit 501. In addition, in the case of the cycle specific state, the cycle timing estimating unit 235 changes the signaled section to be used to the average signaled section calculated by the signaled section averaging unit 503.

The averaging unit 401 performs an averaging process using the average shielding period C _ave for the specific period C ₁ in Expression (1). In the case of the cycle specific state, the mask processing unit 232 performs the mask process using the average shielding cycle C _ave as the specific cycle. When the internal state is the cycle search state, the cycle timing estimating unit 235 sets, as the cycle timing, a time at which the input falling cycle is returned to the past by the signal-existing section as before, and sets the internal state to the cycle specific state. In the case of, the time at which the average falling signal period is returned in the past with respect to the input falling cycle is defined as the cycle timing.

  In the cycle estimating unit 230b, the operation of step S41 is performed after the operation of step S15, the operation of step S42 is performed after the operation of step S16, and the operation of step S43 is performed after the operation of step S17. The order of operation is not limited. For example, in the cycle estimating unit 230b, the operations of step S41, step S42, and step S43 can be performed after step S17.

  In the third embodiment, the hardware configuration of receiving apparatus 200b is the same as that of receiving apparatus 200 of the first embodiment.

  As described above, according to the present embodiment, the cycle estimation section 230b further adds the cycle averaging section 501, the cycle timing averaging section 502, and the signaled section averaging section 503, and performs The cycle timing and the signaled section are averaged. Accordingly, the cycle estimating unit 230b can improve the estimation accuracy of the shielding cycle, the cycle timing, and the section with a signal.

Embodiment 4 FIG.
In the fourth embodiment, the non-periodicity of shielding is determined in the receiving device, and transmission control is performed in accordance with the non-periodicity of shielding in the transmitting device. In addition to performing communication, a situation where the signal is completely shielded is detected to prevent useless transmission. Although it can be applied to any of the first to third embodiments, as an example, a part different from the first embodiment when applied to the first embodiment will be described.

  FIG. 17 is a block diagram illustrating a configuration example of the receiving device 200c included in the communication device 100 according to the fourth embodiment. The receiving apparatus 200c according to the fourth embodiment shown in FIG. 17 is different from the receiving apparatus 200 according to the first embodiment shown in FIG. 2 in that the cycle estimating section 230 is replaced by a cycle estimating section 230c. The cycle estimation unit 230c is obtained by adding a non-cycle determination unit 601 to the cycle estimation unit 230. The operation of the receiving device 200c is the same as the operation of the receiving device 200 of the first embodiment shown in the flowchart of FIG. 3, but differs in the content of the operation of estimating the shielding period in step S3. FIG. 18 is a flowchart illustrating an operation of estimating a shielding period in the period estimating unit 230c according to the fourth embodiment. In the flowchart shown in FIG. 18, the operation from step S11 to step S17 is the same as the operation in the first embodiment shown in the flowchart in FIG.

  The non-periodic determination unit 601 determines the non-periodicity of the occlusion based on the determination result input from the signal determination unit 220, that is, determines whether the signal is always present or not present (step S51). The presence of a constant signal indicates a state where a signal is continuously received, and the absence of a constant signal indicates a state where a signal is not continuously received. Specifically, based on the determination result input from signal determination section 220, non-periodic determination section 601 determines whether or not the signal is continuously received, and indicates whether or not the signal is continuously received. A constant signal absence flag indicating whether or not a signal has been received is generated. The operation of the aperiodic determination unit 601 will be described in detail. FIG. 19 is a flowchart illustrating an operation of determining non-periodicity of occlusion in the non-periodic determination unit 601 according to the fourth embodiment.

The non-periodic determination unit 601 counts the determination result input from the signal determination unit 220 (Step S61). Aperiodic determination unit 601 counts the number of inputs of the determination result input, the input count value and M _in. Further, the non-periodic determination unit 601 counts the number of times that the determination result “1” is input, and sets the count value of the determination result “1” to M ₁ . Further, the non-periodic determination unit 601 counts the number of times the determination result “0” is input, and sets the determination result “0” count value to M ₀ .

Aperiodic determination unit 601, an input count value M _in determines whether match the judgment section E (step S62). Specifically, the aperiodic determination unit 601 determines whether the number of inputs has reached the determination section E. Here, the determination section E indicates the number of input determination results for counting the number of determination results “1” and “0”. When the input count value M _in <the determination section E (No at Step S62), the non-periodic determination unit 601 does not change the always-signal-present flag F _avail and the always-signal-not-flag F _mask from the input time of the determination result, and does not change the value. The always-on signal presence flag F _{avail_old} at the time of input and the always-on signal absence flag F _{mask_old} at the time of input are output (step S63). Aperiodic determination unit 601, when the input count value M _in = judgment section E (step S62: Yes), and counts the number has been reached to the determination section, counts up the determination period count value M _L (step S64).

The non-periodic determination unit 601 performs a threshold determination on the determination result “1” count value M ₁ and the determination result “0” count value M ₀ (step S65). The non-periodic determination unit 601 counts up the shielding count value K _mask when the determination result is “1” count value M ₁ ≦ threshold value H ₁ , and when the determination result is “0” count value M ₀ ≦ threshold value H ₀ , The shielding count value K _avail is counted up. Here, the threshold value H ₁ is a threshold value for the determination result “1” count value M ₁ , and the threshold value H ₀ is a threshold value for the determination result “0” count value M ₀ .

Aperiodic determination unit 601 determines whether or not the judgment section count value M _L is coincident with protection stage N _S aperiodic determination (step S66). Specifically, the non-cycle determining unit 601 determines whether or not the decision interval count value M _L is counted by the input number has reached the protection stage N _S aperiodic determination. Here, protection stage N _S non-periodic determination indicates the number of determination section required aperiodic determination. Aperiodic determination unit 601, if the determination period count value M _L <aperiodic determined protection stage N _S of (step S66: No), the input time point of the firm signal present flag F _avail and firm signal No flag F _mask determination results , And outputs the always-on signal presence flag F _{avail_old} at the time of input and the always-on signal absence flag F _{mask_old} at the time of input (step S63). Aperiodic determination unit 601, if the determination period count value M _L = aperiodic determined protection stage N _S of (step S66: Yes), or non-shielded count value K _avail matches the protection stage N _S non-periodic determination It is determined whether or not it is (step S67).

Aperiodic determination unit 601, if unshielded count value K _avail = aperiodic determined protection stage N _S of (step S67: Yes), firm signal after determination flag indicating F _avail = 1, after the determination at all times no signal flag F _mask = 0 is output (step S68). In the following, the always-signaled flag F _avail after the determination may be simply referred to as the always-signaled flag F _avail, and the always-signal-free flag F _mask after the determination may be simply referred to as the always- _signalless flag F _mask . The constantly signaled flag F _avail = 1 is a constantly signaled flag indicating that the signal is continuously received. Further, the constant signal absence flag F _mask = 0 is a constant signal absence flag indicating that the signal is not in a state of not being continuously received. The state in which the signal is not continuously received is a state in which the signal is continuously received or a state in which the signal is shielded and received periodically. Aperiodic determination unit 601, when the protection stage N _S unshielded count value K _avail <aperiodic determination (step S67: No), whether shielding count value K _mask matches the protection stage N _S non-periodic determination Is determined (step S69). Aperiodic determination unit 601, if the shielding count value K _mask = aperiodic determined protection stage N _S of (step S69: Yes), firm signal present flag F _avail = 0, and outputs a constant signal-free flag F _mask = 1 (Step S70). The always-on signal presence flag F _avail = 0 is an always-on signal presence flag indicating that the signal is not being continuously received. Further, the constant signal absence flag F _mask = 1 is a constant signal absence flag indicating that the signal is not continuously received. The state in which the signal is not continuously received is a state in which the signal is not continuously received or a state in which the signal is shielded and periodically received. Aperiodic determination unit 601, when the protection stage N _S shielding count value K _mask <aperiodic determination (step S69: No), firm signal present flag F _avail = 0, and outputs a constant signal-free flag F _mask = 0 (Step S71). The non-periodic determination unit 601 can generate and output the always-signal-present flag F _avail and the always-signal-not-flag F _mask by the operation of the flowchart shown in FIG.

  Although the case where the operation of the aperiodic determination unit 601 is performed after the operation of the differential processing unit 231 and the operation of the signal interval calculation unit 236 in the cycle estimation unit 230c has been described, the order of the operations of the aperiodic determination unit 601 is limited. Not done. In the cycle estimating section 230c, the operation of the aperiodic determination section 601 may be performed before the operation of the differential processing section 231 to the operation of the section with signal section 236, or the operation of the aperiodic determination section 601 and the differentiation processing section 231. , The operation of the section with signal calculation unit 236 may be performed in parallel.

  In the fourth embodiment, the hardware configuration of receiving apparatus 200c is the same as that of receiving apparatus 200 of the first embodiment.

Next, the operation of the transmitting apparatus 300 that has acquired the always-on signal presence flag F _avail and the always-on signal absence flag F _mask will be described. The configuration of transmitting apparatus 300 of Embodiment 4 is the same as the configuration of transmitting apparatus 300 of Embodiment 1 shown in FIG. However, in the transmitting device 300, the transmission control unit 310 is further _{supplied with the} always-on signal presence flag F _avail and the always-on signal absence flag F _mask from the receiving device 200c.

FIG. 20 is a flowchart illustrating an operation of transmission control in transmission control section 310 of transmitting apparatus 300 according to the fourth embodiment. If the transmission control unit 310 acquires the always-on signal presence flag F _avail = 1 (step S81: Yes), the transmission control unit 310 determines that there is no signal blocking, and determines that the communication device 100 continuously transmits signals (step S81). Step S82). Transmission control section 310 generates a control signal indicating that continuous transmission is performed, and outputs the control signal to transmission signal generation section 320. If the transmission control unit 310 acquires the always-on signal presence flag F _avail = 0 (step S81: No) and acquires the always-on signal absence flag F _mask = 1 (step S83: Yes), the signal is completely shielded. It is determined that the communication device 100 has stopped transmitting the signal from the communication device 100 (step S84). Transmission control section 310 generates a control signal indicating transmission stop and outputs it to transmission signal generation section 320. The transmission control unit 310 periodically acquires the signal presence flag F _avail = 0 (step S81: No), and periodically acquires the signal absence flag F _mask = 0 (step S83: No). Then, it is determined that a burst transmission has been performed (step S85). In this case, transmission control section 310 performs the operation of step S21 shown in the flowchart of FIG. 9 described in Embodiment 1, and determines the transmission start timing and the length of the transmission signal. More specifically, the transmission control section 310 performs control to transmit a burst signal that is a transmission signal having a burst signal length shorter than the length of the signal section. Transmission control section 310 generates a control signal including the determined transmission start timing and transmission signal length, and outputs the control signal to transmission signal generation section 320.

  As described above, according to the present embodiment, in cycle estimation section 230c, aperiodic determination section 601 determines the periodicity of signal blocking, generates a constantly signaled flag and a constantly signalless flag, and transmits the signal. The control unit 310 performs transmission control by using the always-on signal presence flag and the always-on signal absence flag. Specifically, the transmission control unit 310 performs continuous transmission in a situation where there is no signal blocking, stops transmission in a situation where the signal is completely blocked, and has a blocking cycle and a cycle where the signal is periodically blocked. Using the timing and the signal period, the transmission start timing for performing the burst transmission and the length of the transmission signal are determined, and the burst transmission is performed. As a result, the transmission control unit 310 can transmit a signal more efficiently than in a case where the non-periodicity of signal shielding is not used.

Embodiment 5 FIG.
In the fifth embodiment, a receiving apparatus weights a received signal to improve demodulation performance. Although it can be applied to any of the first to fourth embodiments, as an example, a part different from the first embodiment when applied to the first embodiment will be described.

  FIG. 21 is a block diagram illustrating a configuration example of a receiving device 200d included in the communication device 100 according to the fifth embodiment. Receiving apparatus 200d according to the fifth embodiment shown in FIG. 21 is obtained by adding periodic signal generating section 701 and non-signal weighting section 702 to receiving apparatus 200 according to the first embodiment shown in FIG. FIG. 22 is a flowchart illustrating an operation of the reception device 200d according to the fifth embodiment. In the flowchart shown in FIG. 22, the operations from step S1 to step S3 are the same as the operations in the first embodiment shown in the flowchart in FIG.

  The periodic signal generation unit 701 uses the internal state, the shielding period, the period timing, and the signal period acquired from the period estimating unit 230 to generate a periodic signal in which the signal from the communication satellite 104 indicates the shielding period in the receiving device 200d. Is generated (step S91). Specifically, when the internal state is the period search state, the periodic signal generation unit 701 generates a signal fixed at “1” as the periodic signal without using the shielding period, the period timing, and the signal period. When the internal state is the period specific state, the periodic signal generation unit 701 generates a periodic signal using the shielding period, the period timing, and the signal period. FIG. 23 is a diagram illustrating an example of a periodic signal generated by the periodic signal generation unit 701 when the internal state is the specific cycle state in the receiving device 200d according to the fifth embodiment. In FIG. 23, the horizontal axis indicates time, and the vertical axis indicates the value of the periodic signal. The periodic signal generation unit 701 receives the shielding period based on the falling period and the shielding period based on the rising period as the shielding period from the period calculating unit 233 of the period estimating unit 230. A periodic signal as shown in FIG. 23 can be generated using the signaled section. The ideal waveform of the periodic signal shown in FIG. 23 is actually the same as the ideal waveform of the determination result in the signal determination unit 220 shown in FIG.

  The no-signal weighting unit 702 weights the received signal using the periodic signal generated by the periodic signal generation unit 701 (Step S92). Specifically, the no-signal weighting unit 702 sets the weighting target to a received signal in a period in which the periodic signal is “0” (no signal), and multiplies the received signal to be weighted by the weighting coefficient W. Weighting. Here, the weighting coefficient W is a parameter, and the value of the weighting coefficient may be changed depending on whether the received signal is data or pilot. For example, when the received signal to be weighted is a pilot, if the weighting coefficient W is set to W = 0, the noise portion can be masked to “0” in the pilot received in a signal-free section indicating a section where no received signal exists. . As a result, in the receiving apparatus 200d, it is possible to improve the estimation accuracy of the transmission path estimation and the frequency deviation estimated using the pilot at the time of demodulation.

  In the fifth embodiment, the hardware configuration of receiving apparatus 200d is the same as that of receiving apparatus 200 of the first embodiment.

  As described above, according to the present embodiment, in receiving apparatus 200d, periodic signal generation section 701 generates a periodic signal indicating a cycle in which a signal is shielded, and non-signal weighting section 702 generates a periodic signal in the periodic signal. The signal received during the period when it is determined that there is no signal is weighted. By this means, receiving apparatus 200d can give priority to the signal received in the no-signal section and the signal received in the signal-present section, and improve the demodulation performance as compared with the first to fourth embodiments. can do.

Embodiment 6 FIG.
In the sixth embodiment, in transmission apparatus 300 described in the fourth embodiment, transmission control section 310 sets the time when the burst signal length obtained from the signal existence section is less than the minimum burst signal length determined from the transmission frame format. Perform diversity transmission. The parts different from the fourth embodiment will be described.

The configuration of transmitting apparatus 300 of Embodiment 6 is the same as the configuration of transmitting apparatus 300 of Embodiment 4, that is, the configuration of transmitting apparatus 300 of Embodiment 1 shown in FIG. However, in transmission apparatus 300, transmission control section 310 receives, as in the case of the fourth embodiment, always-on signal presence flag F _avail and always-on signal absence flag F _mask from receiving apparatus 200c.

FIG. 24 is a flowchart illustrating an operation of transmission control in the transmission control unit 310 of the transmission device 300 according to the sixth embodiment. In the flowchart shown in FIG. 24, the operations from step S81 to step S84 are the same as the operations in the fourth embodiment shown in the flowchart in FIG. The transmission control unit 310 periodically acquires the signal presence flag F _avail = 0 (step S81: No), and periodically acquires the signal absence flag F _mask = 0 (step S83: No). First, the transmission start timing is determined (step S101). As described above, the method of determining the transmission start timing in the transmission control unit 310 is the same as that of step S21 shown in the flowchart of FIG. 9 described in the first embodiment or step S85 shown in the flowchart of FIG. 20 described in the fourth embodiment. It is the same as the determination method in.

The transmission control section 310 determines the length of the transmission signal, that is, the burst signal length (step S102). The transmission control section 310 determines the burst signal length by, for example, the method shown in FIG. FIG. 25 is a diagram illustrating a method of determining a burst signal length in the transmission control unit 310 according to the sixth embodiment. FIG. 25A is a diagram showing the determination result, in which the horizontal axis represents time and the vertical axis represents the value of the determination result. FIG. 25B is a diagram illustrating a burst signal, in which the horizontal axis indicates time and the vertical axis indicates the transmission level of the burst signal. The transmission control unit 310 obtains the relationship shown in FIG. 25A from the obtained shielding cycle, cycle timing, and signal-existing section. The transmission control unit 310 determines the burst signal length using the signal period A shown in FIG. For example, as shown in (b) shown in the lower part of FIG. 25, the transmission control unit 310 provides a transmission margin of time T ₁ in front of the signaled section A with respect to the signaled section A, It provided the transmission margin of time T ₂ on the rear side of, calculated as the burst signal length _{B c = a-T 1 -T} 2, to determine the burst signal length. The transmission margin of time provided on the front side T ₁ of the signal chromatic interval A and the first time margin, the transmission margin of the time provided in the side T ₂ after signal perforated section A and the second time margin. The transmission control section 310 may control the burst signal transmission level shown in FIG. 25B to output at a specified transmission level, or change the transmission level according to the burst signal length. May be controlled to output.

Transmission controller 310 compares the determined burst signal length B _c and the minimum burst signal length B _min (step S103). Here, the minimum burst signal length B _min indicates the minimum burst signal length that can be transmitted. Transmission control section 310, when the burst signal length B _c ≧ minimum burst signal length B _min (step S103: Yes), determines to perform burst transmission using the transmission signal or burst signal of the burst signal length B _c ( Step S104). Transmission control section 310, determined include a transmission start timing and the burst signal length B _c, to generate a control signal indicating that perform burst transmission, and outputs to the transmission signal generator 320. If the burst signal length B _c <the minimum burst signal length B _min (Step S103: No), the transmission control unit 310 determines to continuously transmit the burst signal by time diversity transmission (Step S105). Transmission control section 310, determined include a transmission start timing and the burst signal length B _c, to generate a control signal indicating that performs time diversity transmission, and outputs to the transmission signal generator 320. The time diversity transmission can be realized, for example, by the transmitting apparatus 300 repeatedly transmitting a signal of a transmission signal unit in the signal-equipped section A or less. Thus, there is a possibility that the device on the receiving side, that is, the communication satellite 104 in the example of FIG. 1, can receive the signal by diversity combining even if the signal is shielded.

  As described above, according to the present embodiment, when the obtained burst signal length is less than the minimum burst signal length, transmission control section 310 performs control for continuous transmission by time diversity transmission. Accordingly, the communication device 100 can perform efficient transmission in a situation where burst transmission cannot be performed due to avoidance of shielding.

Embodiment 7 FIG.
In Embodiment 7, transmission control section 310 has a higher required reception power, that is, a higher required SNR (Signal to Noise Ratio) at the center of the burst signal with respect to the determined transmission signal length, that is, the burst signal length of the burst signal. Symbols are arranged, symbols having a low required SNR are arranged in the first half and the second half of the burst signal, and control for transmitting a signal is performed. The present invention is applicable to any of Embodiments 1 to 6. However, as an example, a part different from Embodiment 1 when applied to Embodiment 1 will be described.

The configuration of transmitting apparatus 300 of Embodiment 7 is the same as the configuration of transmitting apparatus 300 of Embodiment 1 shown in FIG. In transmitting apparatus 300, transmission control section 310 has, as shown in FIG. 26, for example, Q ₁ , Q ₂ , and Q ₃ as symbols having different required SNRs, and the relationship between the required SNRs is Q ₁ <Q ₂ <Q _3. If it is, the Q ₃ is disposed in the center of the burst signal, the Q ₂ are arranged before and after the Q _3, it decides to place the Q ₁ at the beginning and the end side of the burst signal. That is, transmission control section 310 arranges a symbol having a high required SNR at the center of the burst signal, and arranges a symbol having a low required SNR in the first half and the latter half of the burst signal. Transmission control section 310 generates a control signal indicating the determined symbol arrangement, and outputs it to transmission signal generation section 320.

FIG. 26 is a diagram illustrating an example of a symbol arrangement by the transmission control of the transmission control unit 310 in the transmitting apparatus 300 according to the seventh embodiment. In FIG. 26, the horizontal axis indicates time, and the vertical axis indicates the transmission level of the burst signal. Transmitting apparatus 300 determines the arrangement of symbols in the burst signal in the order of Q ₁ , Q ₂ , Q ₃ , Q ₂ , and Q ₁ . As a result, the receiving side device, that is, the communication satellite 104 in the example of FIG. 1, has a probability of being affected by occlusion of Q ₁ > Q ₂ > Q ₃ , so that the average SNR is Q ₁ <Q ₂ <Q ₃ . Become a relationship. For example, even if there is an error in the shielding period, the period timing, and the signal existence section estimated by the period estimating unit 230, the transmission control unit 310 performs the required SNR in the first half and the second half of the burst signal that is likely to be blocked. By arranging symbols with a low SNR and arranging a symbol with a high required SNR at the center of a burst signal that is unlikely to be shielded, the effect of shielding can be reduced and efficient communication becomes possible.

  As described above, according to the present embodiment, transmission control section 310 arranges a symbol having a high required SNR at the center of a burst signal and arranges a symbol having a low required SNR in the first half and the latter half of the burst signal. And Thereby, communication apparatus 100 has a symbol arrangement corresponding to the required SNR, and thus can perform efficient transmission.

  The configurations described in the above embodiments are merely examples of the contents of the present invention, and can be combined with other known technologies, and can be combined with other known technologies without departing from the gist of the present invention. Parts can be omitted or changed.

  Reference Signs List 100 communication device, 101 airframe, 102 rotor, 103 helicopter, 104 communication satellite, 105 ground station, 110 communication system, 200, 200a, 200b, 200c, 200d receiver, 210, 330 antenna, 220 signal determination unit, 230, 230a, 230b, 230c Period estimation unit, 231 differentiation processing unit, 232 mask processing unit, 233 period calculation unit, 234 state determination unit, 235 period timing estimation unit, 236 signal section calculation unit, 300 transmission device, 310 transmission control unit , 320 transmission signal generation section, 401 averaging section, 402 smoothing section, 501 cycle averaging section, 502 cycle timing averaging section, 503 signal section averaging section, 601 aperiodic determination section, 701 cycle signal generation section, 702 Non-signal weighting unit.

Claims (20)

A signal determination unit for determining the presence or absence of a received signal;
Using a determination result of the signal determination unit, a period estimation unit that estimates a shielding period at which a signal transmitted from the source device of the reception signal is blocked,
With
The cycle estimating unit,
A differential processing unit that calculates a differential value of the determination result,
The provisional period of the shielding period is calculated using the derivative value, and based on the internal state indicating the operation state of the period estimation unit, the use of the derivative value and the provisional period is controlled, and the provisional period to be used is output. A mask processing unit,
Using the provisional period output from the mask processing unit, a period calculation unit that calculates the shielding period,
Using the provisional period output from the mask processing unit, a signaled section calculation unit that calculates a signaled section indicating a section in which the received signal is present,
Using the provisional period output from the mask processing unit and the signaled section, a cycle timing for estimating a cycle timing indicating a timing at which the received signal does not exist in the determination result changes to the signaled section in the determination result. An estimator,
Using the shielding period, a state determination unit that determines the internal state,
A communication device comprising: The internal state includes two states: a period search state in which the shielding period is unspecified in the period estimating unit, and a period specifying state in which the shielding period is specified in the period estimating unit. Have
In the cycle estimation unit,
The initial state is the periodic search state,
The transition condition from the cycle search state to the cycle specific state, when the latest shielding cycle calculated by the cycle calculating unit is the reference cycle, the shielding cycle of the past specified number of times the reference cycle. Including within the specified range,
The transition condition from the cycle specific state to the cycle search state, from the time when the specific cycle which is the shielding cycle calculated at the time of the cycle specific state is updated, a period obtained by multiplying the specific cycle by a defined coefficient. When the specific cycle is not updated even after elapse,
The communication device according to claim 1, wherein: When the internal state is the period search state, the mask processing unit does not use the temporary period when the temporary period is not within a range of a specified minimum period and a specified maximum period. In the case of the cycle specific state, do not use the temporary cycle when the temporary cycle is not within the specified range including the specific cycle,
The communication device according to claim 2, wherein: The cycle estimating unit,
When the internal state is the cycle specific state, an averaging unit that averages the determination result or the input value using the specific cycle,
The communication device according to claim 2, further comprising: The cycle estimating unit,
A smoothing unit that smoothes the determination result or the input value based on a specified smoothing number,
The communication device according to any one of claims 2 to 4, further comprising: The smoothing unit performs a smoothing loop L times on the determination result or the input value at time t, and outputs the determination result from the signal determination unit in an n-th smoothing loop process. When the time t represented by the discretized value is time t, the determination result or the input value at time t−n, time t, and time t + 1 is a signal presence, a signal absence, and When there is a signal, the absence of the signal at time t is corrected to the presence of a signal, and the determination result or the input value at time t−n, time t, and time t + 1 indicates no signal, no signal, and no signal, respectively. In this case, the signal at time t is corrected to no signal,
L is an integer of 1 or more; n is an integer of 1 or more and L or less;
The communication device according to claim 5, wherein: The cycle estimating unit,
In the case where the internal state is the cycle specific state, a cycle averaging unit that averages the shielding cycle,
The communication device according to any one of claims 2 to 6, further comprising: The cycle estimating unit,
In the case where the internal state is the cycle specific state, a cycle timing averaging unit that averages the cycle timing,
The communication device according to any one of claims 2 to 7, further comprising: The cycle estimating unit,
In the case where the internal state is the cycle specific state, a signaled section averaging unit that averages the signaled section,
The communication device according to any one of claims 2 to 8, comprising: The cycle estimating unit,
Based on the determination result, a non-continuous signal presence flag indicating whether or not the signal is continuously received and a non-continuous signal absence flag indicating whether or not the signal is continuously received are generated. Period determination unit,
The communication device according to any one of claims 1 to 9, comprising: Using the shielding cycle, the signal-equipped section, the cycle timing, and the internal state, a periodic signal generation unit that generates a periodic signal indicating a cycle in which the signal is shielded,
A no-signal weighting unit that weights the signal received during the period in which it is determined that there is no signal in the periodic signal,
The communication device according to any one of claims 1 to 10, further comprising: In the case where the internal state is the cycle specific state, a transmission control unit that performs control to transmit a burst signal having a burst signal length shorter than the length of the signal interval,
The communication device according to claim 2, comprising: When acquiring a constant signal presence flag indicating that the signal is continuously received from the aperiodic determination unit, a transmission control unit that performs control to continuously transmit a signal from the communication device,
The communication device according to claim 10, further comprising: When acquiring a constant signal absence flag indicating that the signal is not continuously received from the aperiodic determination unit, a transmission control unit that performs control to stop transmission of a signal from the communication device,
The communication device according to claim 10, further comprising: The transmission control unit provides a first time margin before the signal-bearing section, provides a second time margin after the signal-bearing section, and sets the first time margin and the signal margin from the signal-bearing section. The length of the time zone excluding the second time margin is defined as the burst signal length,
The communication device according to claim 12, wherein: The transmission control unit, when the obtained burst signal length is shorter than the minimum transmittable burst length, performs control to continuously transmit the burst signal by time diversity transmission,
The communication device according to claim 15, wherein: The transmission control unit arranges a symbol having a high required reception power at the center of the burst signal, and arranges a symbol having a low required reception power in the first half and the second half of the burst signal.
17. The communication device according to claim 15, wherein: A signal determination unit, a signal determination step of determining the presence or absence of a received signal,
Period estimation unit, using the determination result of the signal determination unit, a period estimation step of estimating a shielding period in which a signal transmitted from the transmission source device of the received signal is blocked,
Including
The cycle estimation step includes:
A first step in which a differentiation processing unit calculates a differentiation value of the determination result;
A mask processing unit calculates a provisional period of the shielding period using the derivative value, and controls the use of the derivative value and the provisional period based on an internal state indicating an operation state of the period estimation unit. A second step of outputting a provisional cycle to be performed;
A third step in which a period calculation unit calculates the shielding period using the provisional period output from the mask processing unit;
A fourth step of calculating a signaled section indicating a section in which the received signal is present, using the provisional period output from the mask processing section,
A cycle timing estimating unit that uses the tentative cycle output from the mask processing unit and the signal-equipped section to indicate a timing at which the determination result changes from a section where the received signal does not exist to a signal-present section in the determination result. A fifth step of estimating timing;
A sixth step in which a state determination unit determines the internal state using the shielding cycle,
A shielding prediction method comprising:   A control circuit for controlling a communication device,
  Using the determination result of the presence or absence of the received signal, in the estimation of the shielding period in which the signal transmitted from the source device of the received signal is blocked,
  Calculation of the differential value of the determination result,
  The provisional period of the shielding period is calculated using the derivative value, and based on an internal state indicating an operation state for estimating the shielding period, the use of the derivative value and the provisional period is controlled. output,
  Using the temporary period, calculating the shielding period,
  Using the provisional period, calculation of a signal presence section indicating a section in which the received signal exists,
  Using the provisional period, and the signal-equipped section, estimation of a cycle timing indicating a timing at which the received signal changes from the section where the received signal does not exist to the signal-emitted section in the determination result,
  Using the shielding cycle, determining the internal state,
  A control circuit for causing a communication device to perform the following.   In a program storage medium storing a program for controlling a communication device, the program includes:
  Using the determination result of the presence or absence of the received signal, in the estimation of the shielding period in which the signal transmitted from the source device of the received signal is blocked,
  Calculation of the differential value of the determination result,
  The provisional period of the shielding period is calculated using the derivative value, and based on an internal state indicating an operation state for estimating the shielding period, the use of the derivative value and the provisional period is controlled. output,
  Using the temporary period, calculating the shielding period,
  Using the provisional period, calculation of a signal presence section indicating a section in which the received signal exists,
  Using the provisional period, and the signal-equipped section, estimation of a cycle timing indicating a timing at which the received signal changes from the section where the received signal does not exist to the signal-emitted section in the determination result,
  Using the shielding cycle, determining the internal state,
  A program storage medium characterized by causing a communication device to execute the following.

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